21001011201021 has 16 divisors (see below), whose sum is σ = 28393125523200. Its totient is φ = 13805642788608.

The previous prime is 21001011200977. The next prime is 21001011201043. The reversal of 21001011201021 is 12010211010012.

It is not a de Polignac number, because 21001011201021 - 2⁹ = 21001011200509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21001011200988 and 21001011201006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001011201721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 107062056 + ... + 107258033.

It is an arithmetic number, because the mean of its divisors is an integer number (1774570345200).

Almost surely, 2^{21001011201021} is an apocalyptic number.

It is an amenable number.

21001011201021 is a deficient number, since it is larger than the sum of its proper divisors (7392114322179).

21001011201021 is a wasteful number, since it uses less digits than its factorization.

21001011201021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214320548.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21001011201021 its reverse (12010211010012), we get a palindrome (33011222211033).

The spelling of 21001011201021 in words is "twenty-one trillion, one billion, eleven million, two hundred one thousand, twenty-one".